Noxious Weeds Found in Ada County

Ada County Weed Pest and Mosquito Abatement

Noxious Weeds Found In Ada County

Click on the links below to learn more about these noxious weeds found in Ada County. If you see a noxious weed while recreating on public lands in Ada County, please immediately contact our office with the location where you spotted the invasive weed. You can contact us by phone at (208) 577-4646 or email weedandpest@adaweb.net.

	Bohemian Knotweed - Can grow up to 12 feet - Egg-shaped leaves with pointed tip - Flowers are clustered with small white flowers		Buffalobur - Contaminant of bird seed - Annual plant with yellow spines and star-shaped hairs - Grows up to 2 feet
	Canada Thistle - Seeds are dispersed by wind - up to 1,000 yards - Can grow to 3 feet tall - Numerous flowers - Roots may be 20 feet deep and 15 feet wide		Dalmatian Toadflax - One plant can produce 1 million seeds - Seeds live up to 10 years - Stems up to 4 feet tall - Bright yellow flowers that are 1-2 inches long
	Diffuse Knapweed - Can grow to 3 feet tall - Stem gives a bushy look - White, pink or sometimes purple disc flowers - Yellowish spine beneath the flower		Dyer's Woad - Source of blue dye - Can grow 3 1/2 feet tall - Flat-topped bright yellow flower clusters - Flowers have four petals - Seeds mature to become purplish-brown
	Eurasian Watermilfoil - Introduced as aquarium plant - Stems are 13-22 feet - Featherlike leaves are dark green to brown, generally with more than 12 leaflet pairs		Field Bindweed - AKA Morning Glory - One of the most noxious weeds in agriculture - White or pink funnel- shaped leaves - Roots creep up to 9 feet deep
	Hoary Alyssum - Four white, deeply notched petals per flower - The plant is covered with grayish-green star shaped hairs - Poisonous to horses		Japanese Knotweed - Can grow up to 9 feet tall - Plant stems zig-zag - Flower clusters droop - Seeds live up to 4 years - Roots can grow up to 18 feet
	Jointed Goatgrass - Winter annual grass - has spikelets that resembles winter wheat - Can grow up to 4 feet tall - Agricultural equipment can disperse the plant's seeds		Leafy Spurge - Milky sap is toxic to humans and horses - Reproduces by seed and creeping roots - A pair of showy, yellowish- green bracts enclose small flower clusters
	Musk Thistle - Seeds can disperse in wind up to 50 yards - Seeds remain viable for up to 10 years - Purple to pink flower grows 1 to 3 1/2 inches long - Stems up to 5 feet tall		Oxeye Daisy - Most seeds die after 6 years, but some survive to 39 years! - Found in pastures and along roadsides - Solitary daisy-like flowers with white petals
	Perennial Pepperweed - Lives in riparian areas, along irrigation ditches and along roadways - Numerous small, white, 4- petalled flowers grow in dense clusters at stem tips		Poison Hemlock - Mistaken for wild carrot - Highly toxic to humans and horses - Seeds disperse far along water - Flowers clump in white umbrella-like clusters
	Puncturevine - AKA "Goatheads" - Seed spine injures humans, animals and get lodged in bicycle tires or shoes - Seeds can survive 20 years - Stems can grow up to 3 feet long		Purple Loosestrife - Flowers are bright pinkish- purple spikes - Grows up to 8 feet tall - Semi-aquatic perennial - Lives in wetlands, stream banks, canal and ditch banks and pond edges
	Rush Skeletonweed - Wiry-branched flower stems - Bush grows up to 3 feet tall - Flowers are bright yellow, star-shaped that grow at the ends of branches - Lower stems have bristly hairs		Russian Knapweed - White, pink or lavender- blue disc flowers on branch tips - Bract beneath the flower is pointed with a green base - Toxic to horses - can cause chewing disease
	Saltcedar - Grows into a shrub or small tree up to 24 feet tall! - Pale or dark pink flowers with five distinct petals - Absorbs a large amount of surrounding water and leeches salt into the soil		Scotch Thistle - Purple or occasionally white disc flowers - Globe-shaped flower head grows 2 inches in diameter - Spine tipped bracts under the flower have cobwebby hairs
	Spotted Knapweed - Produces up to 25,000 seeds per plant! - White or pink-purple flowers - Bract below flower has comb- like fringed margin with black tip		Vipers Bugloss - Toxic to horses and pigs - Purple-blue flowers grow in a funnel shape at the end of a coiled stem - Grows up to 3 feet tall - Leaves have bristly hairs
	Whitetop - Grows up to 2 feet tall - Numerous, white 4-petalled flowers grow in dense, flat- topped clusters at the top of each stem - Plant disperses by creeping root system		Yellow Starthistle - Toxic to horses, causes "chewing disease" - Bright yellow flowers - Bract under the flower has long, sharp spines - Taproot can extend to 6 feet deep

975 E. Pine Ave., Meridian, ID 83642 | ph: 208-577-4646 | fx: 208-577-4631 | weedandpest@adaweb.net

Ada County Weed Pest and Mosquito Abatement

Noxious Weeds Found In Ada County

	Bohemian Knotweed - Can grow up to 12 feet - Egg-shaped leaves with pointed tip - Flowers are clustered with small white flowers		Buffalobur - Contaminant of bird seed - Annual plant with yellow spines and star-shaped hairs - Grows up to 2 feet
	Canada Thistle - Seeds are dispersed by wind - up to 1,000 yards - Can grow to 3 feet tall - Numerous flowers - Roots may be 20 feet deep and 15 feet wide		Dalmatian Toadflax - One plant can produce 1 million seeds - Seeds live up to 10 years - Stems up to 4 feet tall - Bright yellow flowers that are 1-2 inches long
	Diffuse Knapweed - Can grow to 3 feet tall - Stem gives a bushy look - White, pink or sometimes purple disc flowers - Yellowish spine beneath the flower		Dyer's Woad - Source of blue dye - Can grow 3 1/2 feet tall - Flat-topped bright yellow flower clusters - Flowers have four petals - Seeds mature to become purplish-brown
	Eurasian Watermilfoil - Introduced as aquarium plant - Stems are 13-22 feet - Featherlike leaves are dark green to brown, generally with more than 12 leaflet pairs		Field Bindweed - AKA Morning Glory - One of the most noxious weeds in agriculture - White or pink funnel- shaped leaves - Roots creep up to 9 feet deep
	Hoary Alyssum - Four white, deeply notched petals per flower - The plant is covered with grayish-green star shaped hairs - Poisonous to horses		Japanese Knotweed - Can grow up to 9 feet tall - Plant stems zig-zag - Flower clusters droop - Seeds live up to 4 years - Roots can grow up to 18 feet
	Jointed Goatgrass - Winter annual grass - has spikelets that resembles winter wheat - Can grow up to 4 feet tall - Agricultural equipment can disperse the plant's seeds		Leafy Spurge - Milky sap is toxic to humans and horses - Reproduces by seed and creeping roots - A pair of showy, yellowish- green bracts enclose small flower clusters
	Musk Thistle - Seeds can disperse in wind up to 50 yards - Seeds remain viable for up to 10 years - Purple to pink flower grows 1 to 3 1/2 inches long - Stems up to 5 feet tall		Oxeye Daisy - Most seeds die after 6 years, but some survive to 39 years! - Found in pastures and along roadsides - Solitary daisy-like flowers with white petals
	Perennial Pepperweed - Lives in riparian areas, along irrigation ditches and along roadways - Numerous small, white, 4- petalled flowers grow in dense clusters at stem tips		Poison Hemlock - Mistaken for wild carrot - Highly toxic to humans and horses - Seeds disperse far along water - Flowers clump in white umbrella-like clusters
	Puncturevine - AKA "Goatheads" - Seed spine injures humans, animals and get lodged in bicycle tires or shoes - Seeds can survive 20 years - Stems can grow up to 3 feet long		Purple Loosestrife - Flowers are bright pinkish- purple spikes - Grows up to 8 feet tall - Semi-aquatic perennial - Lives in wetlands, stream banks, canal and ditch banks and pond edges
	Rush Skeletonweed - Wiry-branched flower stems - Bush grows up to 3 feet tall - Flowers are bright yellow, star-shaped that grow at the ends of branches - Lower stems have bristly hairs		Russian Knapweed - White, pink or lavender- blue disc flowers on branch tips - Bract beneath the flower is pointed with a green base - Toxic to horses - can cause chewing disease
	Saltcedar - Grows into a shrub or small tree up to 24 feet tall! - Pale or dark pink flowers with five distinct petals - Absorbs a large amount of surrounding water and leeches salt into the soil		Scotch Thistle - Purple or occasionally white disc flowers - Globe-shaped flower head grows 2 inches in diameter - Spine tipped bracts under the flower have cobwebby hairs
	Spotted Knapweed - Produces up to 25,000 seeds per plant! - White or pink-purple flowers - Bract below flower has comb- like fringed margin with black tip		Vipers Bugloss - Toxic to horses and pigs - Purple-blue flowers grow in a funnel shape at the end of a coiled stem - Grows up to 3 feet tall - Leaves have bristly hairs
	Whitetop - Grows up to 2 feet tall - Numerous, white 4-petalled flowers grow in dense, flat- topped clusters at the top of each stem - Plant disperses by creeping root system		Yellow Starthistle - Toxic to horses, causes "chewing disease" - Bright yellow flowers - Bract under the flower has long, sharp spines - Taproot can extend to 6 feet deep

975 E. Pine Ave., Meridian, ID 83642 | ph: 208-577-4646 | fx: 208-577-4631 | weedandpest@adaweb.net